| Mathieu Desnoyers | 068fbad | 2008-02-07 00:16:07 -0800 | [diff] [blame] | 1 | #ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H |
| 2 | #define __ASM_GENERIC_CMPXCHG_LOCAL_H |
| 3 | |
| 4 | #include <linux/types.h> |
| 5 | |
| 6 | extern unsigned long wrong_size_cmpxchg(volatile void *ptr); |
| 7 | |
| 8 | /* |
| 9 | * Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned |
| 10 | * long parameter, supporting various types of architectures. |
| 11 | */ |
| 12 | static inline unsigned long __cmpxchg_local_generic(volatile void *ptr, |
| 13 | unsigned long old, unsigned long new, int size) |
| 14 | { |
| 15 | unsigned long flags, prev; |
| 16 | |
| 17 | /* |
| 18 | * Sanity checking, compile-time. |
| 19 | */ |
| 20 | if (size == 8 && sizeof(unsigned long) != 8) |
| 21 | wrong_size_cmpxchg(ptr); |
| 22 | |
| 23 | local_irq_save(flags); |
| 24 | switch (size) { |
| 25 | case 1: prev = *(u8 *)ptr; |
| 26 | if (prev == old) |
| 27 | *(u8 *)ptr = (u8)new; |
| 28 | break; |
| 29 | case 2: prev = *(u16 *)ptr; |
| 30 | if (prev == old) |
| 31 | *(u16 *)ptr = (u16)new; |
| 32 | break; |
| 33 | case 4: prev = *(u32 *)ptr; |
| 34 | if (prev == old) |
| 35 | *(u32 *)ptr = (u32)new; |
| 36 | break; |
| 37 | case 8: prev = *(u64 *)ptr; |
| 38 | if (prev == old) |
| 39 | *(u64 *)ptr = (u64)new; |
| 40 | break; |
| 41 | default: |
| 42 | wrong_size_cmpxchg(ptr); |
| 43 | } |
| 44 | local_irq_restore(flags); |
| 45 | return prev; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Generic version of __cmpxchg64_local. Takes an u64 parameter. |
| 50 | */ |
| 51 | static inline u64 __cmpxchg64_local_generic(volatile void *ptr, |
| 52 | u64 old, u64 new) |
| 53 | { |
| 54 | u64 prev; |
| 55 | unsigned long flags; |
| 56 | |
| 57 | local_irq_save(flags); |
| 58 | prev = *(u64 *)ptr; |
| 59 | if (prev == old) |
| 60 | *(u64 *)ptr = new; |
| 61 | local_irq_restore(flags); |
| 62 | return prev; |
| 63 | } |
| 64 | |
| 65 | #endif |